Dial M for Multibit: Schiit’s Yggdrasil Analog 2 DAC

In the business of DAC design, Schiit Audio’s Mike Moffat and Jason Stoddard aren’t fans of (what they call) the phantom formats that allow the music industry to endlessly recycle its golden years. Stoddard and Moffat mocked DSD with the (original) Loki and their ‘no, thank you’ on MQA is firmer than a drill sergeant’s handshake.

M is for Moffat.

Ask the charismatic duo about Femto clocks and you’ll likely receive an F-word laden reply: fa-fa-fa-fa-fashion. The digital audio half of the Schiit duo, Mike Moffat, is just as outspoken about delta-sigma DACs. Schiit includes them in their line-up for business reasons but…

M is for multibit.

Moffat is a multibit DAC man at heart but for Schiit’s multibit range, our tall grizzly-man hasn’t opted for an off-the-shelf audio DAC chip, as previously favoured by the likes of Aqua or Audio-gd who, faced with a dwindling PCM1704 supply, have since designed their own multibit modules in-house.

M is for medical.

Moffat’s first multibit Schiit was 2015’s Yggdrasil DAC for which he adapted a quad of medical-grade 20-bit Analog Devices AD5791 chips to handle D/A conversion.

Some Schiit shorthand for ya: Yggy = Yggdrasil, Gumby = Gungnir. Here’s Moffat with the low down on the AD chip breakdown.

“…We adapted weapons/medical-grade chips for a 20 bit x2 per channel on the Yggy (21 bit), 18 bit x2 per channel on the Gumby (19 bit) and 16 bit x1 per channel (16 bit) for the multibit Bifrost”

“However, weapons/medical electronics have no I2S or other internal digital audio protocols so it becomes a fuck-ton of work to adapt them and then figure out how to keep them from glitching. That’s why it took so fuckin’ long.”

“Yggy and Gumby are both a complex multibit design, with two DACs, one a six bit and the other a 14 bit one (12 bit for Gumby) scaled to the 6 bit one. They are both R2R, driving one current switch per bit. Two per channel for both models. The Multibit Bifrost is similar, with the first a 4 bit and the second a 12 bit, one per channel.”

Two chips per channel inside the Yggdrasil signal its fully balanced/differential implementation. The unit’s analogue output spills simultaneously via XLR and (“summed”) single-ended RCA sockets. D/A conversion takes in PCM all the way up to 24bit/192kHz PCM. No DSD. No MQA. No worries.

M is for mathematics.

Like a DAC’s power supply and output stage, the digital filter also plays into its sound quality. The intrinsic iterative nature of delta-sigma calculations means they never quite reach their target. They don’t close. For the Yggdrasil, Moffat journeyed back through the Western Electric archives for 1917 mathematics that would ultimately beget a “unique closed-form digital filter”. Filter calculations here are executed by a SHARC DSP processor, also from Analog Devices, which, according to Moffat, bumps the digital filter’s parts cost beyond that of an entire Bifrost.

Rob Watts highly-acclaimed work for Chord Electronics has steered us towards discussing a digital filter’s tap length. You’ll find 18,000+ in the Yggdrasil’s filter which runs at either 352.8kHz or 384kHz. But the tap length isn’t the key talking point of Moffat’s multibit approach. It’s that the original samples are all retained with freshly calculated samples positioned in between.

Lastly, on the original Yggdrasil’s output stage, Moffat says, “It’s all discrete JFETs, transistors and film caps”.

M is for modular.

This review story didn’t begin in 2018. Schiit first teased the Yggdrasil DAC at RMAF 2014 and officially launched it in 2015. By the time I requested a review unit I was already too late. Schiit was busy fulfilling customer orders; reviewers would have to wait. How refreshing. (I would tackle the multibit Gungnir instead).

Three years down the line, I was quick to report on January 2018’s Analog 2 upgrade but even quicker with a review unit request email. The Analog 2 version holds tight to the original’s digital board but swaps out the original’s analogue board for an improved version:

“Yggdrasil Analog 2 includes many refinements, including all-new Class A, DC-coupled discrete FET buffer stages and completely different internal board structure. The result is increased line driving capability, slightly lower noise and distortion, and…most importantly…significantly better sound!”. So said the January 2018 press release.

Owners of the original Yggdrasil looking to upgrade need not flood the used market. The factory-fitted ‘Analog 2’ board upgrade sells for US$550. A move that jives with Schiit’s inclination toward modular designs that sidestep trade-in programmes.

Six months before that, Schiit announced their Generation 5 USB board, included as standard in all new DAC units but retro-fittable to older units for US$150. Galvanically isolated, the Gen 5 USB board is powered by the DAC itself – not the host device – with “precision crystal local clocking” for both 44.1k and 48k sample rate families. Stoddard reckons Gen 5 is his company’s highest performing USB input to date.

The Gen 5 USB board is in the Analog 2 Yggdrasil and is this reviewer’s preferred digital hook-up with the AURALiC Aries Mini – remember this as we’ll be coming back to it. With the Innuos Zenith MKII SE, we have no choice but to go USB.

M is for made in the USA.

All Schiit gear is made Stateside and without Pacific Rim intervention. I visited their California HQ/factory in October 2016. Since then, Californians have been invited to spend some time at the Schiitr – a retail store in nearby Valencia. For those not so close…

M is for money-back guarantee.

Since the late noughties, Schiit Audio has shown us that the high-margin-low-volume sales model isn’t the only way to turn a profit. Their Stateside direct-sell model, coupled with a fifteen-day money-back guarantee, means customers putting their cash up front can try the Analog 2 Yggy in the comfort of their own home for two weeks, with their own ancillary gear and – for loudspeaker listeners – in a room with which they are familiar.

M is for margins.

Refusing a dealer network means the money that would otherwise go to high street retailers can be passed on in savings to the customer. Savings that have given Schiit the value quotient jump on rival manufacturers who still put their gear in shop windows. Undoubtedly, this is the number one reason why, to my mind, Schiit’s bang/buck exceeds all but Chord Electronics in the sub-$2000 DAC space. These two companies would dominate a list of recommended entry-level DACs were I to make it* [See footnote #1].

The Yggdrasil Analog 2 sells for US$2399.

M is for more gear.

The flagship Schiit DAC was unboxed and carefully lowered onto a vacant Hi-fi Racks Podium Reference shelf where it would sit between Innuos Zenith SE MKII and PS Audio BHK Signature pre-amplifier in the signal path. USB cabling came from Tellurium Q and balanced interconnects from AudioQuest. A second set of AudioQuest interconnects took the PS Audio pre’s output to a pair of Genelec 8341 The Ones, later supplanted by the Kii Three. Both loudspeaker models are fully active. Both go to great lengths with DSP to remove the negative influence of the room.

Taking the room out of the picture completely were a pair of Sennheiser HD800S headphones, connected to the PS Audio pre’s superb headphone output.

Pulled up from their Roon roots by the Innuos Zenith MKII SE were: Al Chem’s Weird Fiction — for its dubbed out electronic fog; Low’s C’mon — for its acoustic instrumentation and mix of female and male vocal); The Wedding Present’s Seamonsters — for quick-paced electric guitar sounds that forever threaten sharp edges; and Daniel Avery’s Song for Alpha — for its Hawtin-aping 303 squiggles and mid-paced tech beats that connote, in the right system, a tremendous sense of inner space.

Not a single one of these titles is available in a hi-res format. It’s Redbook all the way for this review assignment.

M is for Mytek.

Fresh out of the box and then run in for a week, Schiit’s top of the range multibit model evinces with – to borrow from Zu Audio’s terminology – pop and shove aplenty. Dynamics are a strong point. So too are tonal colours – the Yggdrasil’s are some of the most deeply inked I’ve heard at this price point, beating out the Chord Hugo 2 (by a nose) and the Mytek Brooklyn+ (by several lengths).

The Mytek sounds a little flat and grey when held up next to the Analog 2 Yggdrasil; an issue that dissolves once we factor in the Mytek’s furlong-wide feature set. In reproducing the chimes that put us neck-deep in Low’s “Try to Sleep”, the Analog 2 Schiit’s overall gestalt connotes a fast-running stop-motion film of a tree coming into spring blossom. Finger-snap bloom.

M is for memory.

For their recooked flagship, it’s as if Schiit have given the multibit Gungnir’s already standout qualities a shot of adrenalin. Make that two shots. Ease and avidity. Forgiveness with lower-quality source material but knockout detail retrieval — here the Yggdrasil lays down a serious challenge to the Hugo 2’s talents in separating and delineating Daniel Avery’s somewhat simplistic musical layers, both top to bottom but also, for depth, front to back. On Avery’s 90s-nodding electronica (nee: ambient techno) the Yggdrasil’s micro-dynamic jump factor is keenly felt. Very nice.

Through The Wedding Present’s Seamonsters the Yggdrasil runs with a double-shot of espresso. Make that a triple.

Don’t misunderstand this talk of pep. Excitement is high but nerves aren’t shredded. The desire to step down the volume is often the first sign of shitty digital audio. The Yggdrasil pushes my remote control fingering in the other direction.

On aural satisfaction alone, and ignoring feature set, my preference falls first to the Schiit, very closely followed by the Hugo 2 (whose delta could easily be attributed to the lesser USB cable and/or different single-ended interconnects). Pulling up a more remote third is the Mytek. Time to race in the other direction and with another multibit DAC.

Aqua Hifi’s PCM-1704-loaded La Scala MKII sold for €4890 when it debuted in 2014. That’s around US$6000 at today’s rates (that better favour the American buyer). The La Scala remains a stunner ‘round these parts – it’s still here – only usurped by the Optologic edition whose balanced outputs have developed a distortion-inducing fault since my 2017 review. No mind. The original La Scala it is.

David fans baying for Goliath’s blood will be disappointed. The Analog 2 Yggdrasil doesn’t have the low-end reach or mule-kick of the Burr Browned Italian nor its uber-extended top end. Not that you’d notice any shortfall when hearing the Schiit in isolation. That’s not the point anyway. What the Schiit offers for a third of the Aqua’s price is a healthy dose of the La Scala’s core qualities: superb tonality, wide-eyed jump factor and a strong sense of layer separation. Schiit comes within a stone’s throw (NOT a whisker) of the La Scala MKII’s audible talents whilst sat squarely in a different postal code on price.

Such conclusions assume all upstreamers (and their USB wire) remain the same: the Aqua coupled with the Innuos server rings the register at €10,000. Throw down another €1000 for the Tellurium Q Silver Diamond USB. Swap the Aqua out for the big Schiit and we save €3000 but still see our digital front-end cost totalling €7,000. Just as a phono pick-up’s performance will vary according to its host tonearm, a DAC’s sound quality varies according to how jittery or noisy its host streamer.

M is for Mini.

Maximising the Yggdrasil’s filter and D/A conversion opportunities means making data arrival as trouble-free as possible. Here Schiit takes a twin-pronged approach: the galvanically isolated USB input red cards electrical noise taking a joyride along power lines; the internal Adapticlock mechanism – VXCO for low jitter streams, VCO for high jitter – minimises the negative influence of bits arriving early or late. Two technicalities that no doubt feeds into this DAC’s price-expectation-busting performance.

However, as with other DACs, we know that no two USB streamers sound alike. The better ones send less noise out over USB, which, galvanic isolation be damned, can still ride on the data line. In my multibit Gungnir review, I found AURALiC’s Aries to best a MacBook Air and (by quite some margin) a Sonos Connect (over S/PDIF). That was Sydney, 2016.

On another continent, two years later, with the recently updated Yggdrasil doing the tango with different ancillaries, AURALiC’s Aries Mini steps down the Innuos server/streamer’s performance-enhancing druggery. As one might expect from a USB transport that sells for one-tenth of another’s price, micro dynamic avidity takes a hit and tonality suffers minor dilution. You pay less, you get less. My preference still sits with the Aqua La Scala MKII when both it and the Schiit are fed the Aries Mini’s USB output.

M is for mix-n-match.

And this is where our story takes a hook-turn to force a slow down and clearer overview: the Innuos Zenith SE playing into Schiit Yggdrasil Analog 2 sounds marginally more satisfying in the long-term (better tonal colour, more emphatic timing and dynamics) than the AURALiC Aries Mini spilling its USB beans into the original Aqua La Scala MKII. The delta isn’t enormous but it’s my job to zoom in for illustrative purposes to conclude, more emphatically than ever before, that the digital transport matters. Even with high-end DACs. Even with high-end DACs promising jitter-reduction through re-clocking and EMI reduction through galvanic (or optical) isolation. Isn’t this why we’ve seen a proliferation of USB fixer-uppers and re-clockers in recent years?

With the Schiit Yggdrasil Analog 2 we see a DAC with no additional feature set on which to fall back should it materialise as an also-ran at its price point. Buyer appeal is determined solely by its performance as a converter of digital audio to analogue. And boy, does it deliver, cutting us a huge chunk of the high-end’s digital audio cake but without the associated price premium, in turn free-ing more of our budget for a top-flight server/streamer. Because Mike Moffat, multibit, medical, maths and modular. Astonishing for a product made entirely in the US of A.

Footnote #1: I’ve since made it. My list of goto DACs below US$2500 will feature in the fourth Darko.Audio podcast.